Results of the calculation of the absorber temperature in a flat solar air heater
Abstract
The article discusses a method for calculating the temperature of the solar air heater absorber under conditions of still air in the collector and under conditions of low forced convection. The problem of determining the temperature of the air heater absorber tst is considered for the climatic conditions of Fergana, with a horizontal collector and when solar radiation passes through double glass. It is assumed that over the considered short period of time, the temperature of the absorber is constant and the heat loss through the insulation of the bottom of the collector is negligible. Solar radiation passes through ordinary transparent colorless glass with a reflectance of 8%. Taking into account the losses of the heat flux of solar radiation when passing through glass 1 and 2 by the reflection coefficients K 1 and K 2 , in the first version the Stefan-Boltzmann equation is solved, as a result of which the temperature value of the absorber surface is obtained. In the second variant, the absorber temperatures were obtained taking into account convection.